XrmitronK and Harrow1 found that when 2,4,6-tribromophenol was gradually added to conc nitric acid (relative amounts employed are not specified) 2 of the halogen atoms were replaced by nitro groups and that the product was 2,1-dinitro-ij-bromophenol. In a second experiment, when the trihalogenated phenol was dissolved in glacial acetic acid, one molecular proportion of nitric acid added, and the whole heated for some time on the water-bath, the paru bromine atom only mas displaced, and

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... mo-4-nitrophenol was obtained. The use of more nitric acid gave the dinitro compound mentioned above. Claus and Hirsch2 who studied the action of conc. nitric acid on 2,4,6tribromo-m-cresol in glacial acetic acid solution in the cold, isolated a mononitro-dibromo derivative melting with decomposition at 143 ', to which they assigned the structure, 2,6-dibrom0-4-nitro-~it-cresol. Foster'3 working under the direction of Zincke, found that treatment of a glacial acetic acid solution of 2,4,(i-tribromo-wcresol with sodium nitrite gave a yield of 83% of a mononitro-dibromo derivative melting at 1%" (Foster says nothing about decomposition upon melting) to which he gave the structure 2 ,Ci-dibromo-4-nitro-m-cresol, evidently identical with the product obtained by Claus and Hirsch. Zincke4 has summarized this and similar work done by himself and students on the bromine derivatives of ortho, meta and para cresols, and has leached the conclusion that in the meta series this method of nitration give? products in which the halogen atom Fara to hydroxyl is replaced by the nitro group, while in the ortho and para series the atom ortho to hydroxyl is replaced. In no case has he reported the formation of isomeric compounds as the result of a single nitration. It ha5 long been known that phenol and the cresols, except the paru compound, usually give when nitrated a mixture of ortho and para isomerides; but, so far as the author is aware, no one previous to 19105 has recorded the formation of isomeric nitro compounds as a result of the nitration of a halogenated phenol. In 1911 Raifords had occasion to prepare *